Headerduct for cellular floor



Nov. 1, 1966 J. w. HUDSON 3,282,298

HEADERDUCT FOR CELLULAR FLOOR Filed May 14, 1963 2 Sheets-Sheet 1 Nov.l, 1966 J. w. HUDSON 3,282,298

HEADERDUCT FOR CELLULAR FLOOR Filed May 14, 1963 2 Sheets-Sheet 2 UnitedStates Patent O Filed May 14, 1963, Ser. No. 280,233 1 Claim. (Cl.13S-92) This invention relates generally to underfloor wiring duct, andmore particularly to headerduct for contiguous use with multicellularlloors.

An object of the invention is to provide capped access openings fortubular headerduct in a less expensive manner than formerly.

Another object is to provide a simple means of field installation of anaccess unit at a place on a headerduct where no access unit or cappedaccess opening has been provided.

Still another object is to provide means enabling easy eld formation ofrelatively large holes through the bottom of a headerduct and the top ofa floor cell contiguous therewith even though the particular access uniton the headerduct is unusually far out of line or off center from thefloor cell.

Yet another object is to provide an improved headerduct and access unitconstruction wherein the access hole through the top of the headerductis relatively large in relation to the width of the duct and can be madelarger than the width of the duct with respect to the dimension thereoflengthwise of the duct and yet be covered by the access unit.

A further object is to provide an improved headerduct and access unitconstruction wherein the access unit is provided with storage space forspliced wire connections.

A still further object is to provide a headerduct with access openingscapped by substantially llat plates which are respectively replaceableby access units securable to the headerduct by the same fastening meansused to secure the flat plates.

Another object is to provide improved fastening means for securingaccess units or caps for access openings to a headerduct. y

Still another object is to provide an improved access unit having atwo-piece removable cover including an inner cover invertible to providea tile edging and removable for normal -servicing and an outer coverring removable When necessary.

Other objects and advantages will become apparent when the followingspecication is consider-ed along with the accompanying drawings inwhich: j

FIGURE 1 is a fragmentary perspective view of a multicell-ular floor anday headerduct constructed in .accordance with the invention;

FIG. 2 is a fragmentary plan view showing an access unit of theheaderduct of FIG. 1 with the inner cover removed and showing an openingthrough the bottom of the headerduct and the top of a cell of themulti-cellular floor;

FIG. 3 is a fragmentary sectional view taken substantially along theline 3 3 of FIG. 1;

FIG. 4 is a fragmentary brok-en sectional view taken substantially alongthe line 4 4 of FIG. 2, but showing the inner cover in position;

FIG. 5 is a fragmentary sectional View taken substantially along theline 5 5 of FIG. l;

FIG. 6 is a fragmentary sectional View taken substantially along theline 6 6 of FIG. 1, but showing the trim ring and inner cover invertedto form a tile ending; and

FIG. 7 is a plan view similar to FIG. 2 but with the outer cover ringremoved and showing an olf-center hole through the top of a cell of themulti-cellular floor.

FIG. l shows two sections 11 and 12 of multi-cellular steel oor looselyjoined at a joint 13. Contiguous with 3,282,298 Patented Nov. 1, 1966ICC the top of the sections 11 and 12 of multi-cellular floor is alength 14 of headerduct constructed in accordance with the invention.For purposes of illustration, only one access unit 15 and one coverplate 16 for an access opening are shown, it being understood that aplurality of access units 15 and cover plates 16 capping access openingsmay be provide-d in the length 14 of headerduct.

As shown in FIGS. 2, 4, and 7, the access unit 15 is generallyrectangular and is secured at its respective corner portions to theheaderduct 14 by four bolts 18 and associated nuts 19. The bolts 18 areinverted with their heads inside the headerduct and are held captive byformed washers 20 (FIG. 4) which respectively engage the threads of thebolts above square shank portions thereof adjacent the heads. The squareshank portions are respectively received in square holes in theheaderduct to prevent the bolts from turning, as will be understood.

As shown in FIGS. l, 3, and 5, the cover plate 16 for capping an accessopening is rectangular and is secured to the headerduct 14 iby fourbolts 18a and associated nuts 19a arranged in identical fashion to thearrangement of the bolts 18 and nuts 19 securing the access unit 15 tothe headerduct. The cover plate 16 is thus readily replaceable byanother access unit 15.

The cover plate 16 is substantially at, but is preferably beveled at theedges and is dished adjacent the four holes therein which receive thebolts 18a, as shown at 16a in FIG. 5, to provide room for the retainingwashers 20a.

The access unit 15 includes a base portion 22 secured to the headerduct14 by the bolts 18 and nuts 19, an outer cover ring 23, a trim ring 24,and an inner cover 25. The base portion 22 is provided with a generallyU-shaped peripheral portion for receiving a downwardly extendingperipheral flange 23a of the outer cover ring 23, as shown in FIGS. 4and 6.

Four threadedly adjustable support posts 27, one adjacent each corner ofthe base portion 22, are provided for supporting the outer cover ring23. The posts 27 are respectively formed with integral, upwardly-concavecollars 28 for engaging correspondingly shaped portions of the outercover ring 23 which is held on the respective posts 27 by fourspecially-formed recessed nuts 29.

As shown in FIGS. 1 and 2, the tui-ni ring 24 is substantially square.and is secured at its respective conner portions to the outer coverring 23 by four countersunk screws 31. The inner cover 25 is secured attwo diagonally opposite corne-r portions tothe outer cover 23 by a pairj of countersunk screws 32 (FIG. 1). The trim ring 24 land inner cover25- may be installed ilush with the cover ring, yas best shown in FIG.4, olr they may be inverted to provide a tile edging, as shown in FIG.6, upstaniding peripheral ribs 24a and 25e being provided respectivelythereon for this purpose. The inner cover 25 is seated on four resilientsealing strips 34 (FIG. 2) adhesively secured to the outer cover ning23, andthe trim ring 24 is seated on four L-shaped corner ledges 3'5provided on the cover ring 23.

The b-a-se por-tion 22 of lthe access unit 15 is provided with a largeaccess hole dened by a rounded inner edge 37 (FIGS. 2 and 7) having adepending flange portion 38 (FIG. 4) which projects into an accessopening formed in the top of rthe headerduct 14 and is substantiallyflush with the inner surface of the top of the headerduct. in accordancewith the inventi-on, the diameters of the access hole :in the baseportion 22 defined by the inner edge 37 and che corresponding accessopening in the top of the headerduct 14 ane at least seventy-fivepercent of the width of the headerduct itself. This is one of the many`conc-en-tric holes of identical size formed respectively in the bottomof the headerduct 14 and in the top of a cell of the section 11 ofmulticellular oor. As shown in FIG. 2, these holes 39 y.are alsoconcentric with the access hole dened by the inner edge 37 of the baseportion 22 of the access unit 15, and may thus be readily Jformed in theeld with the access unit in place. A plurality of access units 1S wouldnormally be provided along the length of the heade-nduct 14, and wouldbe spaced in accordance with the spacing of the cells of amultiecellullar door. However, because the joints such as the joint 13between various sections of the cellular l'l-oor such as the secti-ons11 and 12 are loose, it is not improbable that occasion-ally an .accessunit 15 will be off center from a cell which it is desired to activate,or use as a wiring raceway, even though at a different point along thelength of the headerduct 14 another cell of the cellular floor will beon center with an access unit 15.

FIG. 7 shows a circle 40 which (represents a pair of concentric holes ofidentical size formed respectively in the bottom of the headerduct 14and in the top of a cell of the cellular ilioor. These 'holes 40` aresimilar to the holes 39, but at their location along the length of theheaderduct 14, the holes 40 are so far off center from the center of theaccess hole 37 in the base portion 22 of the respect-ive access uintthat they could not be formed with the access unit in place. When such acondition arises, the .access unit of this invention may be easilyremoved land the access opening in the top of the headerduct.corresponding to the access hole 37 of the access unit may be enlargedso as to incre-ase its dimension lengthwise of the duct to over onehundred percent of the duct width, .as by cutting the top of theheaderduct away along the dotted line 41. The lholes 40 may then be.readily formed in the bottom of the headerduct and the top of the cell,after which the base portion 22 of the access unit may be secured backin position on the headerduct.

It will be seen that an improved headerduct of the type adapted to bemounted contiguously with steel cellul-ar iloor sections has beenprovided wherein holes may be readily forme-d thnough the 'bottom of theheaderduct and the top of a lloor cell even though the particular accessunit is unusually far off center from the lloor cell. Further, lacontiguous headerduct has been provided on which an access unit may beeasily mounted in the field at a place where no access opening has beenprovi-ded at the factory, simply by forming the proper holes in the topof the headerduct. lIt will further be seen that a contiguous headenducthas been provided wherein the access hole through the top of theheaderduct is relatively large in relation to the width of the ductandcan be made large-r than the width of ythe 'duct with respect to thedimension thereof lengthwise of the duct and still be covered by theaccess unit.

It will also be seen that an improved access unit for a contiguousheaderduct has been provided having storage space for spliced wireconnections and having a two-piece removable cover including an innercover invertible to provide .a tile edging. Also, improved fasteningmeans have been provided for interchangeably securing access units andcapping plates to a contiguous headerduct for multicellular floor.

Various modifications may be rnade in the structure disclosed withoutdeparting trom the spirit and scope oi the invention.

I claim:

In a multi-cellular underfloor duct system including a plurali-ty ofloosely-joined sections of multi-cellular iloor, each section having aplurality of cells the centers of which are equally spaced from onelanother by a p-redetermined distance but the loose yjoining of saidsections permitting cumulative err-ors over a plurality of sections inthe spacing of the center of an end cell of one of said sections fromthe center of the adjacent end cell of an adjacent section as comparedwith said predetermined distance, the improvement comprising a tubularheaderduct of generally rectangular cross section, said headerducthaving a plurality of access openings in a top wall por-tion thereof,the centers of said access openings being equally spaced from oneanother longitudinally of said headerduot by an exact multiple of saidpredetermined distance, land an elongated substantially rectangularaccess unit secured to said headerduct over one of said access openingswith the longer dimension thereof extending longitudinally of saidheaderduct, said longer dimension of said access unit being greater thanthe width of said headerduct, and said access unit being readilyremovable whereby said top wiall portion of said headerduct may be cutaway to enlarge said one of said access openings length? wise of saidheaderduct to a dimension lengthwise of said headerduct greater than thewidth of said headerduct to .compensate for said cumulative errors inthe spacing of the centens of said cells due to said loose joining ofsaid sections of multi-cellular door and said access unit may then besecured back in position to cover said enlarged access opening.

References Cited by the Examiner UNITED STATES PATENTS Re. 25,042 9/1961Blinn et al 13S-92 2,733,036 6/1956 Meletio 50-127 X 2,763,294 9/1956Kennedy 13S-92 2,987,909 6/ 1961 Shlank 220-3.8 X 3,003,794 10/1961Burley 138-92 X 3,029,964 4/1962 Hudson etal 138--92 X 3,070,252 12/1962Reiland 13S- 92 X 3,093,933 6/1963 Slinglu 138-92 X LAVERNE D. GEIGER,Primary Examiner.

LEWIS I. LENNY, Examiner.

T. MOORHEAD, Assistant Examiner.

